부산대학교 도서관

Graphene-based terahertz (THz) polarization converters have recently attracted the attention of researchers, but there are few reports on polarization converters with dynamically tunable and switchable properties. Here, a nanolayered metasurface supported with graphene composed of a pair of elliptical-shaped resonators, a bottom gold layer, and a dielectric spacer is proposed as a switchable polarization convertor. Numerical results demonstrated that the proposed design has the advantages of switching between the half-wave plate (HWP) and a quarter-wave plate (QWP) based on graphene in the THz regime. Also, the polarization conversion ratios (PCR) and ellipticity in both working modes are higher than 90% in wide bands. The surface current distributions provide insight into the mechanism of the bi-functional polarization conversions. Thus, the proposed switchable converter shows excellent polarization imaging and communications prospects.